From f2d7f23a300f57e36cd849ce80a93ccbcebd9968 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 5 Jan 2017 19:43:25 -0200 Subject: Remove i686, x86_64, and powerpc strtok implementations Based on comments on previous attempt to address BZ#16640 [1], the idea is not support invalid use of strtok (the original bug report proposal). This leader to a new strtok optimized strtok implementation [2]. The idea of this patch is to fix BZ#16640 to align all the implementations to a same contract. However, with newer strtok code it is better to get remove the old assembly ones instead of fix them. For x86 is a gain in all cases since the new implementation can potentially use sse2/sse42 implementation for strspn and strcspn. This shows a better performance on both i686 and x86_64 using the string benchtests. On powerpc64 the gains are mixed, where only for larger inputs or keys some gains are showns (based on benchtest it seems that it shows some gains for keys larger than 10 and inputs larger than 32). I would prefer to remove the optimized implementation based on first code simplicity and second because some more gain could be optimized using a better optimized strcspn/strspn code (as for x86). However if powerpc arch maintainers prefer I can send a v2 with the assembly code adjusted instead. Checked on x86_64-linux-gnu, i686-linux-gnu, and powerpc64le-linux-gnu. [BZ #16640] * sysdeps/i386/i686/strtok.S: Remove file. * sysdeps/i386/i686/strtok_r.S: Likewise. * sysdeps/i386/strtok.S: Likewise. * sysdeps/i386/strtok_r.S: Likewise. * sysdeps/powerpc/powerpc64/strtok.S: Likewise. * sysdeps/powerpc/powerpc64/strtok_r.S: Likewise. * sysdeps/x86_64/strtok.S: Likewise. * sysdeps/x86_64/strtok_r.S: Likewise. [1] https://sourceware.org/ml/libc-alpha/2016-10/msg00411.html [2] https://sourceware.org/ml/libc-alpha/2016-12/msg00461.html --- sysdeps/x86_64/strtok.S | 208 ---------------------------------------------- sysdeps/x86_64/strtok_r.S | 5 -- 2 files changed, 213 deletions(-) delete mode 100644 sysdeps/x86_64/strtok.S delete mode 100644 sysdeps/x86_64/strtok_r.S (limited to 'sysdeps/x86_64') diff --git a/sysdeps/x86_64/strtok.S b/sysdeps/x86_64/strtok.S deleted file mode 100644 index 6b32b8a..0000000 --- a/sysdeps/x86_64/strtok.S +++ /dev/null @@ -1,208 +0,0 @@ -/* strtok (str, delim) -- Return next DELIM separated token from STR. - For AMD x86-64. - Copyright (C) 1998-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Based on i686 version contributed by Ulrich Drepper - , 1998. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#include -#include "asm-syntax.h" - -/* This file can be used for the strtok and strtok_r functions: - - strtok: - INPUT PARAMETER: - str %rdi - delim %rsi - - strtok_r: - INPUT PARAMETER: - str %rdi - delim %rsi - save_ptr %rdx - - We do a common implementation here. */ - -#ifdef USE_AS_STRTOK_R -# define SAVE_PTR (%r9) -#else - .bss - .local save_ptr - .type save_ptr, @object - .size save_ptr, LP_SIZE -save_ptr: - .space LP_SIZE - -# ifdef PIC -# define SAVE_PTR save_ptr(%rip) -# else -# define SAVE_PTR save_ptr -# endif - -# define FUNCTION strtok -#endif - - .text -ENTRY (FUNCTION) - /* First we create a table with flags for all possible characters. - For the ASCII (7bit/8bit) or ISO-8859-X character sets which are - supported by the C string functions we have 256 characters. - Before inserting marks for the stop characters we clear the whole - table. */ - movq %rdi, %r8 /* Save value. */ - subq $256, %rsp /* Make space for 256 bytes. */ - cfi_adjust_cfa_offset(256) - movl $32, %ecx /* 32*8 bytes = 256 bytes. */ - movq %rsp, %rdi - xorl %eax, %eax /* We store 0s. */ - cld - rep - stosq - - /* Note: %rcx = 0 !!! */ - -#ifdef USE_AS_STRTOK_R - /* The value is stored in the third argument. */ - mov %RDX_LP, %R9_LP /* Save value - see def. of SAVE_PTR. */ - mov (%rdx), %RAX_LP -#else - /* The value is in the local variable defined above. But - we have to take care for PIC code. */ - mov SAVE_PTR, %RAX_LP -#endif - movq %r8, %rdx /* Get start of string. */ - - /* If the pointer is NULL we have to use the stored value of - the last run. */ - cmpq $0, %rdx - cmove %rax, %rdx - testq %rdx, %rdx - jz L(returnNULL) - movq %rsi, %rax /* Get start of delimiter set. */ - -/* For understanding the following code remember that %rcx == 0 now. - Although all the following instruction only modify %cl we always - have a correct zero-extended 64-bit value in %rcx. */ - -L(2): movb (%rax), %cl /* get byte from stopset */ - testb %cl, %cl /* is NUL char? */ - jz L(1) /* yes => start compare loop */ - movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ - - movb 1(%rax), %cl /* get byte from stopset */ - testb $0xff, %cl /* is NUL char? */ - jz L(1) /* yes => start compare loop */ - movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ - - movb 2(%rax), %cl /* get byte from stopset */ - testb $0xff, %cl /* is NUL char? */ - jz L(1) /* yes => start compare loop */ - movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ - - movb 3(%rax), %cl /* get byte from stopset */ - addq $4, %rax /* increment stopset pointer */ - movb %cl, (%rsp,%rcx) /* set corresponding byte in stopset table */ - testb $0xff, %cl /* is NUL char? */ - jnz L(2) /* no => process next dword from stopset */ - -L(1): - - leaq -4(%rdx), %rax /* prepare loop */ - - /* We use a neat trick for the following loop. Normally we would - have to test for two termination conditions - 1. a character in the stopset was found - and - 2. the end of the string was found - As a sign that the character is in the stopset we store its - value in the table. The value of NUL is NUL so the loop - terminates for NUL in every case. */ - -L(3): addq $4, %rax /* adjust pointer for full loop round */ - - movb (%rax), %cl /* get byte from string */ - testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ - jz L(4) /* no => start of token */ - - movb 1(%rax), %cl /* get byte from string */ - testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ - jz L(5) /* no => start of token */ - - movb 2(%rax), %cl /* get byte from string */ - testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ - jz L(6) /* no => start of token */ - - movb 3(%rax), %cl /* get byte from string */ - testb %cl, (%rsp,%rcx) /* is it contained in stopset? */ - jnz L(3) /* yes => start of loop */ - - incq %rax /* adjust pointer */ -L(6): incq %rax -L(5): incq %rax - - /* Now we have to terminate the string. */ - -L(4): leaq -4(%rax), %rdx /* We use %rDX for the next run. */ - -L(7): addq $4, %rdx /* adjust pointer for full loop round */ - - movb (%rdx), %cl /* get byte from string */ - cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ - je L(8) /* yes => return */ - - movb 1(%rdx), %cl /* get byte from string */ - cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ - je L(9) /* yes => return */ - - movb 2(%rdx), %cl /* get byte from string */ - cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ - je L(10) /* yes => return */ - - movb 3(%rdx), %cl /* get byte from string */ - cmpb %cl, (%rsp,%rcx) /* is it contained in skipset? */ - jne L(7) /* no => start loop again */ - - incq %rdx /* adjust pointer */ -L(10): incq %rdx -L(9): incq %rdx - -L(8): cmpq %rax, %rdx - je L(returnNULL) /* There was no token anymore. */ - - movb $0, (%rdx) /* Terminate string. */ - - /* Are we at end of string? */ - cmpb $0, %cl - leaq 1(%rdx), %rcx - cmovne %rcx, %rdx - - /* Store the pointer to the next character. */ - mov %RDX_LP, SAVE_PTR - -L(epilogue): - /* Remove the stopset table. */ - addq $256, %rsp - cfi_adjust_cfa_offset(-256) - retq - -L(returnNULL): - xorl %eax, %eax - /* Store the pointer to the next character. */ - mov %RDX_LP, SAVE_PTR - jmp L(epilogue) - -END (FUNCTION) diff --git a/sysdeps/x86_64/strtok_r.S b/sysdeps/x86_64/strtok_r.S deleted file mode 100644 index f0db78c..0000000 --- a/sysdeps/x86_64/strtok_r.S +++ /dev/null @@ -1,5 +0,0 @@ -#define FUNCTION __strtok_r -#define USE_AS_STRTOK_R 1 -#include -weak_alias (__strtok_r, strtok_r) -strong_alias (__strtok_r, __GI___strtok_r) -- cgit v1.1